[R] ggplot using scale_x_date gives Error in seq.int(r1$year, to$year, by)

[Aidan Corcoran]

Dear all,

ggplot gives me an error when trying to plot time series data using a
date variable as the x axis.

g<-structure(list(Date = c("2011-12-23", "2011-12-30", "2012-01-06",
"2011-12-23", "2011-12-30", "2012-01-06", "2011-12-23", "2011-12-30",
"2012-01-06"), variable = structure(c(1L, 1L, 1L, 2L, 2L, 2L,
3L, 3L, 3L), .Label = c("Price", "Yield", "CDS Spread"), class = "factor"),
    value = c(86.777, 86.037, 86.437, 9.737, 9.542, 9.683, 580.132,
    576.866, 573.564)), .Names = c("Date", "variable", "value"
), row.names = c(100L, 101L, 102L, 202L, 203L, 204L, 304L, 305L,
306L), class = "data.frame")

> g
          Date   variable value
100 2011-12-23      Price  86.8
101 2011-12-30      Price  86.0
102 2012-01-06      Price  86.4
202 2011-12-23      Yield   9.7
203 2011-12-30      Yield   9.5
204 2012-01-06      Yield   9.7
304 2011-12-23 CDS Spread 580.1
305 2011-12-30 CDS Spread 576.9
306 2012-01-06 CDS Spread 573.6
> gp<-ggplot(g,aes(x=Date,y=value,group=variable,lty=variable)) +geom_line()
> gp
> #THIS WORKS FINE (BUT AXIS LABELLING NOT VISIBLE WITH MORE DATA, HENCE I WOULD LIKE TO USE SCALE_X_DATE)
> gp<-gp+   scale_x_date()
> gp
Error in seq.int(r1$year, to$year, by) : 'from' must be finite
In addition: Warning messages:
1: In get(x, envir = this, inherits = inh)(this, ...) :
  NAs introduced by coercion
2: In min(x) : no non-missing arguments to min; returning Inf
3: In max(x) : no non-missing arguments to max; returning -Inf
4: In min(x) : no non-missing arguments to min; returning Inf
5: In max(x) : no non-missing arguments to max; returning -Inf
>

In previous help requests, the workaround of specifying the unit was suggested:
gp<-gp+   scale_x_date(major="years")
but this doesn't work for me (same error).

Any help is very much appreciated! Thanks in advance.

Aidan

R version 2.14.1 (2011-12-22)
Platform: i386-pc-mingw32/i386 (32-bit)

locale:
[1] LC_COLLATE=English_Ireland.1252  LC_CTYPE=English_Ireland.1252
LC_MONETARY=English_Ireland.1252
[4] LC_NUMERIC=C                     LC_TIME=English_Ireland.1252

attached base packages:
 [1] datasets  tools     grDevices grid      splines   graphics  stats
    tcltk     utils
[10] methods   base

other attached packages:
 [1] micEcon_0.6-6      miscTools_0.6-12   np_0.40-11
cubature_1.0       boot_1.3-3
 [6] RODBC_1.3-3        sqldf_0.4-6.1      chron_2.3-41
gsubfn_0.5-7       DBI_0.2-5
[11] Haver_1.0          xtable_1.5-6       plm_1.2-7
sandwich_2.2-7     MASS_7.3-16
[16] Formula_1.0-1      nlme_3.1-102       bdsmatrix_1.0
RBloomberg_0.4-150 rJava_0.9-1
[21] gtools_2.6.2       gdata_2.8.2        ggplot2_0.8.9
proto_0.3-9.2      zoo_1.7-4
[26] reshape_0.8.4      plyr_1.6           svSocket_0.9-52
TinnR_1.0.3        R2HTML_2.2
[31] Hmisc_3.8-3        survival_2.36-10

loaded via a namespace (and not attached):
[1] cluster_1.14.1        digest_0.5.0          lattice_0.20-0
RSQLite_0.10.0
[5] RSQLite.extfuns_0.0.1 svMisc_0.9-63
>